ACADEMY OF NATURAL SCIENCES. 373 



defined specimen of a zeolite has yet been found within the borders of California. 



Another curious fact in the mineralogy of California is the occurrence of some 

 mineral species which are common as ores in other mining countries, and which 

 in California, or at least in the mining region of the Sierra Nevada, are dis- 

 seminated through a great number of localities, but nowhere exist in workable 

 quantity. Galena and blende may be particularly referred to as occurring in 

 this way. There is hardly a gold-bearing vein in the Sierra which has not some 

 galena and blende in fine particles in the veinstone ; but not a locality is known 

 where the quantity of either of these ores is anything like sufficient to justify 

 mining, even were the other conditions as favorable as in the Eastern States or 

 in Europe. Galena occurs in considerable quantity in the extreme south-eastern 

 portion of the State, or just over the borders, in Arizona and Nevada ; but no 

 considerable deposit of zinc blende has yet been made known anywhere in the 

 Pacific States or Territories ; nor is any other ore of zinc known to occur in 

 workable quantity on this coast. 



The mineral region with which ours most nearly agrees, in the character of its 

 ores and mineral substances, is that of the South American Andes, especially of 

 Chile. In Mr. David Forbes' recent catalogue of the Chilean minerals, there 

 are about two hundred species enumerated, of which about sixty have hitherto 

 been discovered in California aud the other Pacific States and Territories. The 

 Chilean mineral list, like that of California, is remarkable for the absence of 

 many of the almost universally distributed silicates mentioned above as wanting 

 in the Pacific States, namely : beryl, topaz, zircon, Wollastonite, Allanite, iolite, 

 staurotide, kyanite, spodumene, spinel and datholite. Many other silicates, 

 abundantly distributed throughout other portions of the world, might be men- 

 tioned as entirely wanting along the whole Pacific Coast. Several of the more 

 common zeolites are found in the Chilean list, which are wanting in California; 

 while several others are equally wanting in both countries. Among the com- 

 mon zeolites found in Chile which have nut vet been discovered in California 

 are Prehnite, stilbite, Laumontite and scolecite ; while analcime, harmotome, 

 Thomsonite, natrolite and Heulandite are wanting there as well as here. 



It is evident, from a comparison of the mineral lists of the States situated 

 along the Pacific Coast of North and South America, that there has been a 

 most remarkable resemblance in the conditions which have influenced the form- 

 ation and segregation of the accidental minerals now found accompanying the 

 stratified and eruptive masses throughout the whole vast extent of the regions 

 in question. This is another of the facts which go to show the unity of the 

 Cordilleras of North and South America as a geological result. 



Mr. Bolander stated that the absence of many mineral species 

 from this coast found its parallel in a similar absence of many 

 botanical groups. 



Dr. Cooper did not think there was any poverty with respect to 

 animal species on this coast, and suggested that the absence of cer- 

 tain groups of plants might be due to the absence of certain appro- 

 priate mineral constituents from the soil. 



